The StopForumSpam extension allows wikis to utilize and contribute data to stopforumspam.com. It features automatic IP blocking, confidence variables, and an easy interface for administrators to submit data. Use of the IP blacklist requires that you use some kind of object caching; it won't work if you have $wgMainCacheType set to CACHE_NONE.

When blocking a user, a checkbox will appear to submit the user's data. Data will only be submitted if the user is logged in, has an email address set, and has an IP address stored. This feature requires either $wgPutIPinRC to be enabled, or the CheckUser extension installed.

You can download IP blacklists, and import them using the updateBlacklist.php script. If that IP tries to edit, or a user tries to edit through that IP address, they will be prevented from editing. To exempt a user from being blocked, give them the sfsblock-bypass userright. This feature requires object caching to be setup.